/*
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 * and open the template in the editor.
 */

package servlets;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import presenter.Presenter;

/**
 *
 * @author root
 */
@WebServlet(name = "FileDownload", urlPatterns = {"/FileDownload"})
public class FileDownload extends HttpServlet {
    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
         final String path = Presenter.PATH;
               String fileName = request.getParameter("fileName");
	        if(fileName == null || fileName.equals("")){
	            throw new ServletException("File Name can't be null or empty");
	        }
                
	        File file = new File(path+File.separator+fileName);
	        if(!file.exists()){
	            throw new ServletException("File doesn't exists on server.");
	        }
	        System.out.println("File location on server::"+file.getAbsolutePath());
	        ServletContext ctx = getServletContext();
	        InputStream fis = new FileInputStream(file);
	        String mimeType = ctx.getMimeType(file.getAbsolutePath());
	        response.setContentType(mimeType != null? mimeType:"application/octet-stream");
	        response.setContentLength((int) file.length());
	        response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
	 
	        ServletOutputStream os  = response.getOutputStream();
	        byte[] bufferData = new byte[1024];
	        int read=0;
	        while((read = fis.read(bufferData))!= -1){
	            os.write(bufferData, 0, read);
	        }	        os.flush();	        os.close();
                fis.close();
	        System.out.println("File downloaded at client successfully");

    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
        
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}